Welding is used in various manufacturing and construction applications to join various metal pieces together to form a unitary piece. An arc welding system typically includes an electric power supply coupled to a welding gun that houses an electrode that is located in the handle. The electrode completes an electrical circuit with a source of power when the electrode is placed against a piece of metal to be welded. The contact between the electrode and the piece of metal produces an electric arc between the electrode and the metal piece. The heat of the electric arc is concentrated on the metal piece, or pieces, to be joined, thereby melting the metal piece(s). A filler material is added to the molten metal, which subsequently cools and solidifies, joining the metal pieces together.
Metal Inert Gas (MIG) welding is one type of arc welding. MIG welding is also referred to as “wire feed” or Gas Metal Arc Welding (GMAW). In MIG welding a metal wire is used as the electrode to produce the arc. The wire is shielded by an inert gas and the metal wire acts as the filler for the weld. The inert gas is used to shield the electric arc from contaminants and gases that may react with the weld. Typically, the wire and gas are fed through a hand-held welding gun. The wire and gas are fed to the welding gun from a welding system having a wire feeder, a power source and a source of gas.
A robotic MIG welding gun assembly typically includes a main body mountable on a robotic arm, a gooseneck, and a contact tip assembly. Alternatively, the MIG welding gun may include a handle for gripping by a human operator. A flexible cable is connected to a rearward end of the main body to supply gas, electrical current, and a consumable electrode (e.g., a metal welding wire) to the gun. The cable may be connected to a wire feeder opposite the main body. The gooseneck is operatively connected to a forward end of the main body and allows for the communication of the consumable electrode, the shielding gas, and the welding current to the contact tip assembly mounted on the gooseneck.
The MIG welding gun may include a locking nut that can be loosened to adjust the position of the contact tip assembly relative to the handle of the gun by rotating the gooseneck relative to the handle. However, loosening of the locking nut also allows the gooseneck to be freely removed from the welding gun, with or without authorization.